Lithium batteries, with metallic lithium electrodes, have limited life-cycle due to the degradation of the metallic lithium electrodes. Lithium is attacked and/or passivated by electrolytes. This results in formation of lithium powder with a very high surface area at the interface between the metallic lithium and the electrolyte. The formation of high surface area lithium powder is undesirable because it reacts violently with moisture and air.
In U.S. Pat. No. 4,464,447, Lazzari et al have proposed using a material of the formula Li.sub.x M.sub.2 O.sub.3 to prepare a negative electrode (anode) where M is Fe. This approach has certain limitations because the reversible capacity of such electrode appears to be rather small. In U.S. Pat. No. 5,147,739, issued Sep. 15, 1992, Beard et al suggested a composite negative electrode (anode) which includes a first phase which is an intermediate intercalation material (Li.sub.x CoO.sub.2) and a second phase which is metallic lithium. Although the intercalation material is said to have the general formula Li.sub.x M.sub.a X.sub.b, Beard identifies only Li.sub.x CoO.sub.2 with X having a value of 0&lt;x.ltoreq.1.0. Beard conjectures that other intercalation materials based on transition metal oxides, including manganese, might be suitable for use with metallic lithium. Beard does not describe what the specific values of x, a, and b should be for an intercalation material other than the Li.sub.x CoO.sub.2. Since Beard's anodes include a metallic lithium phase, such anodes do not solve the problem of metallic lithium electrodes. In U.S. Pat. No. 5,135,732, Barboux et al suggested a method to produce lithiated manganese oxide and lithiated cobalt oxide for use as positive electrodes (cathodes) in cells having lithium metal anodes. These cathode formulations are capable of intercalating lithium, but such cathodes do not address the problem of metallic lithium anodes.
Therefore, what is needed is an improved anode which is an alternative to present metallic lithium anodes and which simultaneously fulfills the requirements of high reactivity, good charge rate capabilities and cycle life, low specific weight, stability, and low cost.